Actualy if you don't like either: Linhoff used leather, I don't think there is much diverence unless you want to keep it on a non-metal camera for an extended time, either the glue sticks or the rubber....
Leather can allso be used if the cork gives up.

I have GAS too:
- Rolleiflex 2.8F
- Rollei SL 66
- Sinar P2 8x10 inch
- OM 1n